FL Studio Mobile - Create & save multi-track music projects on a smartphone
ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Splice Beat Maker - Make and share beats in your browser
7Pad Scales and chords - Music instrument and assistant for playing scales and chords.
Sampulator - Make (and record) beats on your keyboard
Scale Heaven - Browse and play any scale/chord, chord progression.